Absorption edge

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(Discontinuité, arête d'absorption (Fr). Absorptionskante (Ge). Canto de absorción (Sp). край поглощения (Ru). Spigolo di assorbimento (It)


Definition

An absorption edge is a sharp discontinuity in the absorption spectrum of X-rays by an element that occurs when the energy of the photon corresponds to the energy of a shell of the atom (K, LI, LII, LIII, etc.).


Examples

For gallium:

λK = 1.1958 Ǻ; \lambda_{L_{I}} = 9.5446 Ǻ; \lambda_{L_{II}} = 10.8414 Ǻ; \lambda_{L_{III}}= 11.1038 Ǻ;

For arsenic:

λK = 1.0448 Ǻ; \lambda_{L_{I}} = 8.1195 Ǻ; \lambda_{L_{II}} = 9.1187 Ǻ; \lambda_{L_{III}}= 9.3617 Ǻ;


See also

Section 4.2.3 of International Tables of Crystallography, Volume C